1. Field of the Invention
The present invention relates to a vertical CMOS image sensor, and more particularly, to a CMOS image sensor that uses blue photoelectric conversion characteristics of a p-n junction body having an n-characteristic and a p-characteristic of thiophene derivatives.
2. Description of the Related Art
An image sensor is a photoelectric transducer that detects light and transforms the detected light into an electric signal. A conventional image sensor includes a plurality of unit pixels arranged in arrays on a semiconductor substrate. Each of the unit pixels includes a photodiode and transistors. The photodiode generates and stores optical charges by detecting external light. The transistors output electrical signals in response to the amount of optical charges generated from the photodiode.
A complimentary metal oxide semiconductor (CMOS) image sensor includes a photodiode that may receive and store optical signals, and may display an image using a control device that may control or process the optical signals. The CMOS image sensor has advantages in that it may be manufactured using a simple manufacturing process since the control device may be manufactured using a conventional CMOS manufacturing technique, and furthermore, the CMOS image sensor may be manufactured on one chip along with various signal processing devices.
In a conventional CMOS image sensor, the photodiode includes a color filter that transmits light of a particular wavelength. The color filter absorbs approximately ⅔ of light incident on the photodiode, and thus, the amount of light input to the photodiode is reduced, which may cause a reduction in sensitivity of the CMOS image sensor.
A CMOS image sensor that does not use a color filter has been disclosed in U.S. Patent Publication No. 2005/0194653. In this CMOS image sensor, vertically-stacked photodiodes generate electrical signals.
Also, a CMOS image sensor that does not use a color filter has been disclosed in U.S. Patent Application NO. 2005/0205903. In this CMOS image sensor, a photoelectric conversion film is used as a photoelectric conversion unit.